Observation of NLIW in the South China Sea using PIES
Abstract
Long-term goals are to study the mechanisms of generation, evolution and propagation of high frequency nonlinear internal waves [NLIW] in the vicinity and west of Luzon Strait in the South China Sea, making use of pressure equipped inverted echo sounders. Our objectives are (1) to observe the internal tide propagating west of Luzon Strait and its progressive evolution in shape and speed as it traverses the South China Sea under the influence of nonlinearity, non-hydrostatic effects, rotation, topography, currents and stratification, and (2) to interpret the results with the help of models that incorporate these effects. Our approach involved deployment of three modified pressure equipped inverted echo-sounders [PIES], set up to transmit every 6s (see Fig.1). These instruments measure the return acoustic travel time from sea-floor to surface, which is modified by variations in the local stratification resulting from passage of internal waves. Knowledge of the background stratification is provided by CTD casts. Time series measurements of the acoustic travel time then provide a basis for inferring the first mode internal response. The observations are analyzed with 2-layer models: a weakly nonlinear and also a fully nonlinear model of the wave evolution process, a model of the wave generation mechanism and a coupled model in which the wave generation is coupled to the fully nonlinear evolution model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2010
- Accession Number
- ADA542693
Entities
People
- David M. Farmer
Organizations
- University of Rhode Island